This invention relates to a video editing apparatus and method, and more particularly to a video editing apparatus and method wherein editing points such as a mark-in point and a mark-out point are set for a video sequence. More specifically, the present invention relates to a video editing apparatus and method wherein an editing point is set for a plurality of video sequences imaged from multiple angles with the same time base.
Video editing apparatus of the type mentioned are conventionally known, and one of the related art video editing apparatus employs two video tape recorders of the analog type.
In the video editing apparatus of the structure just described, one of the video tape recorders is used to play back a video tape (hereinafter referred to as material video tape) on which a video signal is recorded as a source video sequence in advance, and a motion picture based on the reproduced video signal is displayed on a monitor.
Then, an operator of the video editing apparatus visually observes the motion picture displayed on the monitor to select a video clip, and the other video tape recorder is used to record a video signal corresponding to the selected video clip (the video signal is hereinafter referred to as clip video signal) onto the other video tape (hereinafter referred to as clip video tape).
In this manner, the video editing apparatus can successively repeat an editing process including selection of a video clip and recording of a clip video signal corresponding to the selected video clip to produce a clip video tape on which a plurality of video clips are recorded.
The video editing apparatus is required to record clip video signals successively reproduced from a clip video tape in a predetermined order onto the clip video tape, so that the clip video signals may be broadcast as they are as motion pictures of a predetermined broadcasting program.
Therefore, the video editing apparatus is sometimes required to perform a fast feeding or rewinding operation of a material video tape using one of the video tape recorders. Further, when it is intended to produce video clips using a plurality of material video tapes, the video editing apparatus is sometimes required to successively exchange the material video tapes to play them back using just one of the video tape recorders, resulting in a complicated editing operation.
In recent years, a video editing apparatus has been proposed which employs, as a recording medium of a source video sequence, a non-linear medium having a great capacity and multiple accessibility, such as a hard disk, and employs a graphical user interface.
In a video editing apparatus of the type mentioned, since a non-linear medium is used, a plurality of source video sequences recorded in advance on the non-liner medium can be accessed at random. The video editing apparatus is advantageous in that it eliminates the necessity for such complicated operation required by the video editing apparatus described first as a fast feeding or rewiring operation of a material video tape on one of two video tape recorders or an exchanging operation of a material video tape.
The video editing apparatus is advantageous also in that, since it employs a graphical user interface, it can select video clips successively and at random, that is, scenes of a motion picture each between an editing start point (hereinafter referred to as mark-in point) and editing end point (hereinafter referred to as mark-out point) are designated by a mark-in point and a mark-out point on a motion picture displayed on a monitor, and an order of the selected video clips can be determined on the monitor in accordance with the necessity, whereby the efficiency in editing operation can be augmented.
Further, in the video editing apparatus, a time line representative of the time base is provided on the graphical user interface. An editing operator used to paste a video sequence or a video clip, which is an object of editing, onto the time line and perform an editing operation of setting editing points such as a mark-in point and a mark-out point on the time line.
However, while the name of a video sequence or a video clip can be displayed on the time line, it cannot be discriminated what video data a video frame has from the display of the time line. In order to decide a desired editing point, the editing operator performs operation of designating a suitable point on the time line by means of a mouse and confirming an image of a video frame at the point designated using the mouse. In short, the operation to decide an editing point must be repeated until a desired video image is found out.
If the duration of a video sequence or a video clip of an editing object is as short as several seconds, then the editing operation of deciding an editing point may not require very much time. However, if the duration of a video sequence or a video clip of an editing object is several tens minutes or several hours, then since the number of video frames whose videos must be confirmed is huge, very long time is required for the operation of deciding an editing point.
It is an object of the present invention to provide a video editing apparatus and method by which an editing operation for setting an editing point of a video sequence or a video clip can be performed rapidly and efficiently.
In order to attain the object described above, according to a video editing apparatus and a video editing method of the present invention, a video browser for browsing video frames of a video sequence being supplied is produced and the produced video browser is displayed in a coordinated relationship to the time base on a monitor, and then a graphical user interface which allows editing points such as an editing start point and an editing end point set for the video sequence to be displayed in a coordinated relationship to the video browser is produced. Accordingly, even if the video sequence which is an object of editing is, for example, a very long video sequence, images of individual video frames of the video sequence can be confirmed readily from the video browser. Consequently, editing points can be determined in a short time.
More particularly, according to an aspect of the present invention, there is provided a video editing apparatus for setting an editing point for a video sequence, including a means for successively sampling vertical lines of video frames of the video sequence to produce vertical slits and successively arranging the vertical slits as video images representing the individual video frames in a horizontal direction to produce a video browser for browsing the video sequence, a display means for displaying the video browser on a monitor, and an editing means for setting an editing point for the video sequence in a coordinated relationship to the time base of the video browser.
According to another aspect of the present invention, there is provided a video editing apparatus for setting an editing point for a video sequence, including a video browser production means for producing a video browser for browsing the video sequence based on vertical video images obtained by sampling video frames of the video sequence in a vertical direction, a display means for displaying the video browser on a monitor, and an editing point setting means for setting an editing start point and an editing end point in a coordinated relationship to the video browser displayed by the display means.
The video editing apparatus may be constructed such that the video browser production means further produces an audio waveform representative of a level of an audio signal corresponding to the video sequence, and the display means displays the audio waveform in a coordinated relationship to the video browser in the time base direction together with the video browser.
Preferably, the video browser production means successively shifts the sampling position of the vertical video image in a horizontal direction for the individual video frames.
The display means may display video browsers produced from a plurality of video sequences having the same time base in a coordinated relationship to each other.
According to a further aspect of the present invention, there is provided a video editing method for setting an editing point for a video sequence, comprising the steps of producing a video browser for browsing the video sequence based on vertical video images obtained by sampling video frames of the video sequence in a vertical direction, displaying the video browser on a monitor, and setting an editing start point and an editing end point in a coordinated relationship to the video browser displayed on the monitor.
The video editing method may be constructed such that, wherein, when the video browser is produced, an audio waveform representative of a level of an audio signal corresponding to the video sequence is also produced, and the produced audio waveform is displayed together with the video browser in a coordinated relationship to the video browser in the time base direction.
The vertical video images which form the video browser may be video data sampled from positions of the individual video frames successively shifted in a horizontal direction.
A plurality of video browsers produced from a plurality of video sequences having the same time base may be displayed in a coordinated relationship to each other.
With the video editing apparatus and method of the present invention, a video browser for browsing video frames of a video sequence supplied is produced, and a graphical interface constructed such that editing points such as a mark-in point and a mark-out point set for the video sequence can be displayed in a coordinate relationship to the time base of the video browser is shown on a monitor. Accordingly, even if the video sequence is, for example, a very long video sequence, video images can be confirmed in a short time from the video browser, and consequently, the editing points can be decided in a short time. Further, where video sequences of a plurality of channels are displayed at a time, editing points can be set readily even for a plurality of video sequences imaged from multiple angles and having the same time base.
The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements denoted by like reference symbols.